bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/decorators/DecorationBuilder.java

package org.eclipse.ui.internal.decorators;
/************************************************************************
Copyright (c) 2000, 2002 IBM Corporation and others.
All rights reserved.   This program and the accompanying materials
are made available under the terms of the Common Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/cpl-v10.html

Contributors:
	IBM - Initial implementation
************************************************************************/

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.viewers.IDecoration;

/** 
 * The Decoration builder is the object that builds
 * a decoration.
 */
class DecorationBuilder implements IDecoration {

	private static int DECORATOR_ARRAY_SIZE = 5;

	private List prefixes = new ArrayList();
	private List suffixes = new ArrayList();
	private ImageDescriptor[] descriptors =
		new ImageDescriptor[DECORATOR_ARRAY_SIZE];
	LightweightDecoratorDefinition currentDefinition;

	//A flag set if a value has been added
	private boolean valueSet = false;

	DecorationBuilder() {
	}


	/**
	 * Set the value of the definition we are currently 
	 * working on.
	 * @param definition
	 */
	void setCurrentDefinition(LightweightDecoratorDefinition definition) {
		this.currentDefinition = definition;
	}

	/**
	 * @see org.eclipse.jface.viewers.IDecoration#addOverlay(org.eclipse.jface.resource.ImageDescriptor)
	 */
	public void addOverlay(ImageDescriptor overlay) {
		int quadrant = currentDefinition.getQuadrant();
		if (descriptors[quadrant] == null)
			descriptors[quadrant] = overlay;
		valueSet = true;
	}

	/**
	 * @see org.eclipse.jface.viewers.IDecoration#addPrefix(java.lang.String)
	 */
	public void addPrefix(String prefixString) {
		prefixes.add(prefixString);
		valueSet = true;
	}

	/**
	 * @see org.eclipse.jface.viewers.IDecoration#addSuffix(java.lang.String)
	 */
	public void addSuffix(String suffixString) {
		suffixes.add(suffixString);
		valueSet = true;
	}

	/**
	 * Clear the current values and return a DecorationResult.
	 */
	DecorationResult createResult() {
		DecorationResult newResult =
			new DecorationResult(
				new ArrayList(prefixes),
				new ArrayList(suffixes),
				descriptors);

		return newResult;
	}


	/**
	 * Clear the contents of the result so it can be reused.
	 */
	void clearContents() {
		this.prefixes.clear();
		this.suffixes.clear();
		this.descriptors = new ImageDescriptor[DECORATOR_ARRAY_SIZE];
		valueSet = false;
	}

	/**
	 * Return whether or not a value has been set.
	 * @return boolean
	 */
	boolean hasValue() {
		return valueSet;
	}

}